The present invention relates generally to chemical sensors, and more particularly, to a chemical sensor that employs antibody coated oscillators.
There exists a need for chemical sniffers that have high selectivity, low false signal rate, and high sensitivity, on the order of one part in 10.sup.8 -10.sup.9. Sensitive chemical detectors are desired for drug and contraband detection, and explosives detection, including plastic explosives and dynamite. Additionally, chemical sensors may be used in the environmental cleanup and hazardous material field. Chemical detectors exist that are highly specific, including devices such as spectrum analyzers, for example, but such devices have relatively low sensitivity levels. Chemical detectors also exist that are very sensitive, but these are not specific enough to one chemical (low selectivity), thus increasing false signal rates.
Dr. George Guilbault, at the University of New Orleans, has experimented with coating quartz crystal oscillators with antibodies. His research is discussed in a paper entitled "Immobilization Methods For Piezoelectric Biosensors," published in Bio/Technology, Vol. 7, April 1989, pages 349-351. However, these oscillators must be corrected for temperature, pressure, and humidity. The experiments must be done in a laboratory because of sensitive corrections that are required. These corrections result in a decreased sensitivity in such devices.
Accordingly, it would be an advantage in the chemical detection art to have a detector that is both selective and highly sensitive and that may be employed outside controlled laboratory conditions.